Suffolk Constabulary has said that although the three people have been quizzed about what went on, no arrests have been made at this stage.

More people will be spoken to by officers pursuing the inquiry after damage was caused on March 17.

Various incidents occurred during the evening which led to police and firefighters being sent to the school in Maidstone Road.

Graffiti was scrawled on walls and furniture. This included writing and lewd pictures on walls of stairwells, toilets, classrooms and corridors, and also on some current students’ work.

Plaster was pulled from walls in a corridor, toilets were blocked with toilet paper and attempts made to flood the lavatories.

Fire alarms were set off and people were found smoking in the toilets.

Anne-Marie Breach, a spokeswoman for Suffolk Constabulary, said: “We have interviewed three people in relation to the damage at Orwell High School.

“Enquiries are continuing and a number of other people will be interviewed in due course as the investigation into what happened continues.”

The open event had been billed as a last chance for former students, teachers and members of the community to look round the building before it is demolished later this year.

However, the event turned sour when a group – said to be in their 40s and 50s – started causing trouble and the school had to be evacuated and the evening ended.

School officials said they could not let people back into the building because the automatic alarm system had to be switched off after the fire alarms were activated.

People at the event said that those causing trouble had been drinking before arriving.

The school is currently still in use as the Maidstone Campus of Felixstowe Academy, which will vacate the premises next month to move into its new £20million building in Walton High Street.

On display were memorabilia, old photos and records, while historian and former teacher Phil Hadwen spoke to people about the history of the school, which opened in 1947 as the Felixstowe Secondary Modern School.

A similar event planned for the old Deben High School in Garrison Lane the following night was immediately cancelled.

The academy is looking at how this might be rearranged in a different way to avoid a similar situation taking place.